title: [Removal of PO4(3-) from solution, wastewater and seawater by modification and granulation magnesium and aluminium layered double hydroxide].
abstract: Powder layered double hydroxide of Mg-Al LDH were prepared by hydrothermal technology with 500 kg x batch(-1), modified and granulated (MG Mg-Al CLDH) by deposition method. After the modification and granulation, the fixed bed can not be accumulated and clogged by the adsorbents. The PO4(3-) is removed from aqueous solution, wastewater and seawater by MG Mg-Al CLDH with column experiments. It shows that MG Mg-Al CLDH is an effective adsorbent. After removal, the water quality can satisfy with the first degree of integrated wastewater discharge or seawater standards. The mechanism of removal PO4(3-) is ion exchange and 'memory effect'. The breakthrough adsorption capacity of PO4(3-) from solution is 13.49 mg x g(-1), more than 6 times higher than that by Mg-Al LDH without modification. The exhausted MG Mg-Al CLDH can be desorbed with 0.1 mol x L(-1) NaOH and 3 mol x L(-1) NaCl and regenerated with 25% MgCl2. The regeneration rate is 126.24%. The breakthrough curves are influenced by bed depth, flow rate, initial concentration and initial pH. The adsorption processes are controlled by film diffusion. When the initial concentration is as low as 0.38 micromol x L(-1), PO4(3-) can be removed from seawater to satisfy with the first degree of seawater quality. So this work is very useful for the practical application of Mg-Al LDH and the removal of phosphorus.
authors.affiliation: Environmental Protection Association of Zibo, Zibo 255003, China. kunxing125@163.com
authors.forename: Kun
authors.initials: K
authors.lastname: Xing
authors.forename: Hai-Zeng
authors.initials: HZ
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D008276:Magnesium Hydroxide / Q000737:chemistry*; D010710:Phosphates / Q000032:analysis / Q000302:isolation & purification*; D012623:Seawater / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D000536:Aluminum Hydroxide; D008276:Magnesium Hydroxide; D010710:Phosphates; D062065:Wastewater; D014874:Water Pollutants, Chemical